(Beam) Commissioning Plan Ryoichi Miyamoto Scientist (AD/BPOD/BP) SRR 1 – Ion Source & LEBT 2018-07-17--18

Systems under focus during beam commissioning (1) Objectives of beam commissioning: Adjust parameters of components and achieve required beam parameters. Characterize the beam with diagnostics devices. Relations with beam parameters and components: Beam parameters Source components LEBT components Energy High-voltage Current Magnetron H2 injection Iris Pulse shape Solenoids Chopper Repetition rate (Chopper) Size (envelope) (Magnetron) (H2 injection) N2 injection Trajectory Steerers

Systems under focus during beam commissioning (2) Plasma chamber Extraction system Pumping box Solenoid 2 x steerer Gate valve Iris Diagnostics tank Chopper EMU H+V Faraday cup NPM H+V Doppler shift 2 x TMP Repeller ACCT Commissioning tank (RFQ) HV power supply Isolation transformer Collimator Magnetron H2 bottle Ion source LEBT 1 LEBT 2 3 x solenoid Waveguide Primary pump High voltage (HV) platform Low energy beam transport (LEBT) PSS0 controlled area and radiation shielding Front End and Magnets Cooling water Vacuum PSS Beam Diagnostics Control system Voltage divider HV controls Ground potential controls Beam stop Alternative location of beam instruments for commissioning N2 bottle ACCT: AC current transformer EMU: Emittance measurement unit NPM: Non-invasive profile monitor TMP: Turbomolecular pump

Table of contents System Requirements (2 complements) Specific safety systems Operating & safety procedures Test & Verification (Commissioning overview) Open issues

Complements to system requirements: Current The presented requirements on proton current were: 74 mA out of the source, and 70 mA out the LEBT. These include educated guesses for the worst case losses in the LEBT and RFQ. Extracting too much current could spoil beam quality with the space charge force. The current out of the RFQ shouldn't exceed ~63 mA. 84 mA (100 mA total) simulation (old extraction electrode position) 70 mA (83 mA total) simulation (new extraction electrode position)

Complements to system requirements: Beam modes ISrc < 100 mA ~1000-3000 µs 5-2860 µs ~100 µs LEBT Beam modes 6-70 mA Mode Current [mA] Duration [µs] Rep [Hz] Probe ~6 ≤ 5 ≤ 1 Fast tuning ≤ 62.5 ≤ 14 Slow tuning ≤ 50 Long pulse verification ≤ 2860 ≤ 1/30 Production 2860 14 ~0.1+20 µs 5-2860 µs ~0.1 µs RFQ 6-63 mA MEBT 6-62.5 mA ~0.01 µs 5-2860 µs ~0.01 µs

Tests and verifications: Takeaways from the off-site commissioning Source demonstrated capability of producing up to ~80 mA of protons. Source demonstrated great flexibility and a wide operation range. Some diagnostics devices missed commissioning. Understanding between the source parameters and beam parameters could be improved. Beam transport (steering and matching) in LEBT wasn't thoroughly tested due to lack of time. Beam modes production wasn't thoroughly tested due to lack of time. An issue was found for the chopper and re-design is ongoing. For further details, see ESS-0190279 ("Off-site commissioning report for the ESS proton source and LEBT", under review).

Tests and verifications: Lund commissioning overview 6(+1) steps for ~3 months: Systems verifications with beam (~3 weeks) Source characterization (at mid-point) (~3 weeks) (Chopper and 2nd EMU installation and test) (~1 week) LEBT optics tuning (steering and solenoids scan) (~2 weeks) Beam modes verifications (~2 weeks) Source and LEBT integrated optimization (~2 weeks) Long-term stability tests (~2 weeks) Single 8 hours shift per day. (Possibility to do occasional multiple shifts in a day isn't excluded.) Available duration depends on the RFQ schedule. Planning and tracking of activities are conducted with Jira tool. Documents: ESS-0149990: "Normal-conducting linac beam commissioning scenarios and steps" (approved). ESS-0123228: "ISrc and LEBT beam commissioning plan" (under development)

Test and verifications: Overview in Jira tool

Planning and progress tracking: Activities sequence in Jira tool Activities (sub-steps) under each step are defined in sequence down to half shift.

Planning and progress tracking: Details of each activity are being developed

Tests and verifications: LEBT commissioning layout #1 Layout is changed twice during commissioning BCM - FC - EMU (H) - EMU (V) - NPM (H) - NPM (V) - Dpl - NPM (H) - NPM (V) - BCM - EMU (V) - NPM (H) - NPM (V) - FC Source extraction Solenoid 1 (Steerer 1) Iris Chopper Permanent tank Solenoid 2 (Steerer 2) Collimator Commissioning tank Beam stop

Tests and verifications: LEBT commissioning layout #2 BCM - FC - EMU (H) - EMU (V) - NPM (H) - NPM (V) - Dpl - NPM (H) - NPM (V) - BCM - EMU (V) - NPM (H) - NPM (V) - FC Source extraction Solenoid 1 (Steerer 1) Iris Chopper Permanent tank Solenoid 2 (Steerer 2) Collimator Commissioning tank Beam stop

Tests and verifications: LEBT commissioning layout #3 BCM - FC - EMU (H) - EMU (V) - NPM (H) - NPM (V) - Dpl - NPM (H) - NPM (V) - BCM - EMU (V) - NPM (H) - NPM (V) - FC Source extraction Solenoid 1 (Steerer 1) Iris Chopper Permanent tank Solenoid 2 (Steerer 2) Collimator Commissioning tank Beam stop

Outstanding issues Issues were already covered in talks of each system.

Backup

Test and verification: Configurations from off-site commissioning Section Parameter Unit '17-Nov '17-Sept '17-Sept (Alt) ISrc RF W 420 650 1220 H2 sccm 3.75 3.80 4.75 Sol 1 A 109.0 104.2 108.6 Sol 2 67.2 69.0 68.1 Sol 3 232.0 230.0 244.6 HV kV 75.132 LEBT N2 1.0 0.0 A (mT) 275.0 (228.0) 300.0 (248.7) 299.0 (247.9) 320.0 (265.3) 150.0 (124.4) 202.0 (167.5) Steerer 1H Steerer 1V 2.0 Steerer 2H Steerer 2V 15.0 10.0

Tests and verifications: Goals of each commissioning step (1) Systems verifications with beam (~3 weeks) Complete basic verification tests of all diagnostics devices. Verify that the iris is functioning. Verify that the configurations from the off-site commissioning reproduce similar currents (in the commissioning tank) and emittances (in the permanent tank). Source characterization (at mid-point) (~3 weeks) Test effects from source parameters and N2 injection level on the beam, while stopping the beam in the permanent tank, and establish working points (at least 3) of the source and N2 injection for a later step. Sample emittance vs solenoid 1 (in the permanent tank) for the selected working points of the source and N2 injection. Test and establish steering to the permanent tank. Test beam quality vs source repetition rate. (Chopper and 2nd EMU installation and test) (~1 week) Complete installation and hardware testing of the chopper and its power supply. Verify the temporary and or final chopper with the beam.

Tests and verifications: Goals of each commissioning step (2) LEBT optics tuning (steering and solenoids scan) (~2 weeks) Verify linear optics. Establish steering in the whole LEBT (for any given solenoids configuration). Establish solenoids scan. Beam modes verifications (~2 weeks) Establish capabilities to adjust repetition rate, pulse length, and current and thus to produce the required beam modes. Attempt repetition rate adjustments with the source itself, with the chopper, and with the source and chopper combined. Study carefully the sensitivity of chopping efficiency against the chopper voltage, trajectory, and solenoid 2 strength. Test the matching condition for intermediate currents. Test the fast beam interlock system. Rehearse the procedure for the first injection into the RFQ. Source and LEBT integrated optimization (~2 weeks) Check the matching condition for the working points of the source and N2 injection, prepared in Step 2. Long-term stability tests (~2 weeks) Verify stability of the source.

Tests and verifications: LEBT layout during operations BCM - FC - EMU (H) - EMU (V) - NPM (H) - NPM (V) - Dpl - NPM (H) - NPM (V) - BCM Source extraction Solenoid 1 (Steerer 1) Iris Chopper Permanent tank Solenoid 2 (Steerer 2) Collimator